In a working paper earlier this year, Justin Wolfers and I suggested that there was more than sampling error at work in Australian opinion polls, and that they suffered from systemic biases. The latest ACNielsen poll – showing Labor 54% and the Coalition 46% – appears to support the point. I can’t find a sample size reported anywhere, but if we assume 1500, then the poll implies that if an election were held today, Beazley would be a 99.9% chance of becoming PM (for an example of how to convert polls into probabilities, see this table). If you don’t believe Labor’s true odds could possibly be 99.9%, then you have to believe that the ACN sample isn’t a representative slice of the population.
For poll-lovers, Bryan Palmer is tracking the various polls here. For poll-sceptics, Centrebet has a market open for the 2007 election, with the Coalition a 63% chance, and Labor a 37% chance. These probabilities sound more like the real world to me.